Oil prices slip further - Dec. 7, 1998 - CNNMoneyBrent crude for January delivery on London's International Petroleum Exchange dipped to $9 94 a barrel Oil on average this year, at $13 56 for Brent, is lower than at any time since 1976 Markets are smothered by an enormous stock overhang created by a demand collapse in Asia, an unusually warm 1997-98 winter, rising Iraqi exports and a badly-timed lifting of OPEC's output ceiling a year ago